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From: Kenneth
Subject: dark appearance of uploaded .png images
Date: 10 Apr 2014 15:00:00
Message: <web.5346e9cf4c1152aac2d977c20@news.povray.org>
I'm beginning to think that there is something wrong with my computer/monitor
set-up (Windows XP on a CRT monitor): The .png images that various POV-Ray users
are uploading to the newsgroups look 'dark' on my system, and I have no idea
what the cause is. (Well, I'm guessing that the images *should* look brighter,
although I don't know for sure.)

This dark appearance shows up in a range of applications, not just a specific
one-- the latest Firefox (v28.0); my older Photoshop; and in Windows' Picture
And Fax Viewer. My own .png images made in POV-Ray look fine on my system, as do
..jpegs.

To better show this, I've made .jpeg screenshots of two recent uploaded images,
by FractRacer and Pekka Aho. They are accurate reproductions of how the .png
originals appear on my end. Can someone compare my .jpegs to the original
uploads, to see if they visually match?


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image_comp.jpg


 

From: Ger
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 15:32:59
Message: <5346f1eb$1@news.povray.org>
Kenneth wrote:

> I'm beginning to think that there is something wrong with my
> computer/monitor set-up (Windows XP on a CRT monitor): The .png images
> that various POV-Ray users are uploading to the newsgroups look 'dark' on
> my system, and I have no idea what the cause is. (Well, I'm guessing that
> the images *should* look brighter, although I don't know for sure.)
> 
> This dark appearance shows up in a range of applications, not just a
> specific one-- the latest Firefox (v28.0); my older Photoshop; and in
> Windows' Picture And Fax Viewer. My own .png images made in POV-Ray look
> fine on my system, as do ..jpegs.
> 
> To better show this, I've made .jpeg screenshots of two recent uploaded
> images, by FractRacer and Pekka Aho. They are accurate reproductions of
> how the .png originals appear on my end. Can someone compare my .jpegs to
> the original uploads, to see if they visually match?


Check your monitor calibration with http://www.lagom.nl/lcd-test/

-- 

Ger


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From: Ger
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 15:43:16
Message: <5346f454$1@news.povray.org>
Ger wrote:

> Kenneth wrote:
> 
>> I'm beginning to think that there is something wrong with my
>> computer/monitor set-up (Windows XP on a CRT monitor): The .png images
>> that various POV-Ray users are uploading to the newsgroups look 'dark' on
>> my system, and I have no idea what the cause is. (Well, I'm guessing that
>> the images *should* look brighter, although I don't know for sure.)
>> 
>> This dark appearance shows up in a range of applications, not just a
>> specific one-- the latest Firefox (v28.0); my older Photoshop; and in
>> Windows' Picture And Fax Viewer. My own .png images made in POV-Ray look
>> fine on my system, as do ..jpegs.
>> 
>> To better show this, I've made .jpeg screenshots of two recent uploaded
>> images, by FractRacer and Pekka Aho. They are accurate reproductions of
>> how the .png originals appear on my end. Can someone compare my .jpegs to
>> the original uploads, to see if they visually match?
> 
> 
> Check your monitor calibration with http://www.lagom.nl/lcd-test/
> 

Or for a CRT you could also use http://www.displaycalibration.com/

Hope that helps you out.
-- 

Ger


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From: Pekka Aho
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 16:10:00
Message: <web.5346fa0bcd1600b6d4f68260@news.povray.org>
My latest image was actually quite dark already to begin with, thus what I see
in the .jpg now here on my end doesn't differ at all from the original .png file
that I posted. I admit of course that I've got a general tendency to produce
images rather dark in colors when I try to capture certain feelings, atmospheres
etc. But I can try something a bit brighter next time as well for a change, no
worries at all. =)


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From: FractRacer
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 16:20:25
Message: <5346fd09$1@news.povray.org>

> I'm beginning to think that there is something wrong with my computer/monitor
> set-up (Windows XP on a CRT monitor): The .png images that various POV-Ray users
> are uploading to the newsgroups look 'dark' on my system, and I have no idea
> what the cause is. (Well, I'm guessing that the images *should* look brighter,
> although I don't know for sure.)
>
> This dark appearance shows up in a range of applications, not just a specific
> one-- the latest Firefox (v28.0); my older Photoshop; and in Windows' Picture
> And Fax Viewer. My own .png images made in POV-Ray look fine on my system, as do
> ..jpegs.
>
> To better show this, I've made .jpeg screenshots of two recent uploaded images,
> by FractRacer and Pekka Aho. They are accurate reproductions of how the .png
> originals appear on my end. Can someone compare my .jpegs to the original
> uploads, to see if they visually match?
>
  The image seems normal, it is like povray has rendered, it is a night 
scene with a shining star...
Is, for you, the center of the star white? And the trees dark? If yes, 
all is right.
Have you seen the image of Kurt Le Pirate: black and white stripes?
How appear this image on your screen?

Lionel.

-- 
Do not judge my words, judge my actions.

---

http://www.avast.com


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From: Alain
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 19:10:47
Message: <534724f7$1@news.povray.org>

> I'm beginning to think that there is something wrong with my computer/monitor
> set-up (Windows XP on a CRT monitor): The .png images that various POV-Ray users
> are uploading to the newsgroups look 'dark' on my system, and I have no idea
> what the cause is. (Well, I'm guessing that the images *should* look brighter,
> although I don't know for sure.)
>
> This dark appearance shows up in a range of applications, not just a specific
> one-- the latest Firefox (v28.0); my older Photoshop; and in Windows' Picture
> And Fax Viewer. My own .png images made in POV-Ray look fine on my system, as do
> ..jpegs.
>
> To better show this, I've made .jpeg screenshots of two recent uploaded images,
> by FractRacer and Pekka Aho. They are accurate reproductions of how the .png
> originals appear on my end. Can someone compare my .jpegs to the original
> uploads, to see if they visually match?
>

I also have a CTR monitor, and those images also look dark on my side. 
With CTR monitors, you NEED to set the brightness quite low, often to 
the lowest setting, to prevent bluring and bleeding. That's not the case 
when using LCD, or plasms, monitors.

"Normal" settings for CRT are usualy contrast at the highest value and 
brightness set so that a totaly black display stays /just/ black. With 
those settings, the dark images are very dark unless brightned using 
post processing.

As for your images, YOU created them much brighter BECAUSE your display 
is darker.



Alain


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From: Kenneth
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 23:10:01
Message: <web.53475cbecd1600bc2d977c20@news.povray.org>
FractRacer <lg.### [at] gmailcom> wrote:

>   The image seems normal, it is like povray has rendered, it is a night
> scene with a shining star...
> Is, for you, the center of the star white? And the trees dark? If yes,
> all is right.

Yes, that's how it appears to me. The thing that made me question your image's
appearance (on my system) is that I thought I was missing the 'details' of the
image. I took it into Photoshop and used 'levels' to brighten it up somewhat,
and was able to see many more details-- which is what I thought everyone else
was seeing ;-)

> Have you seen the image of Kurt Le Pirate: black and white stripes?
> How appear this image on your screen?

That one appears perfectly normal. I didn't think to check if it was a .png
image; I'll take another look.


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From: Kenneth
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 23:15:00
Message: <web.53475da1cd1600bc2d977c20@news.povray.org>
Ger <No.### [at] ThankYou> wrote:

>
> Or for a CRT you could also use http://www.displaycalibration.com/
>

Thanks. I'll check that out. (Before now, I haven't *noticed* any odd problems
with my monitor-- but calibrating it is a good idea.)


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From: Kenneth
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 23:20:01
Message: <web.53475e3ccd1600bc2d977c20@news.povray.org>
"Pekka Aho" <pek### [at] gmailcom> wrote:
> My latest image was actually quite dark already to begin with, thus what I see
> in the .jpg now here on my end doesn't differ at all from the original .png file
> that I posted.

Thanks; that's a relief to know. (Nice image, BTW!) As I mentioned in another
reply here, I thought I was missing some details that others were seeing (based
on their comments about your image.)


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From: Kenneth
Subject: Re: dark appearance of uploaded .png images
Date: 10 Apr 2014 23:55:01
Message: <web.5347672ccd1600bc2d977c20@news.povray.org>
Alain <kua### [at] videotronca> wrote:
>
> I also have a CTR monitor, and those images also look dark on my side.
> With CTR monitors, you NEED to set the brightness quite low, often to
> the lowest setting, to prevent bluring and bleeding. That's not the case
> when using LCD, or plasms, monitors.
>
> "Normal" settings for CRT are usualy contrast at the highest value and
> brightness set so that a totaly black display stays /just/ black. With
> those settings, the dark images are very dark unless brightned using
> post processing.

That thought occurred to me, that the differences between CRT and LCD/LED
monitors might be part of the problem: creating the image on one type of
monitor, but viewing it on another. Years ago, I bought an LCD monitor-- but
took it back within days, as its color rendition/contrast were just too...
'different'... from what I was used to on my CRT.
>
> As for your images, YOU created them much brighter BECAUSE your display
> is darker.
>

I was wondering about that, too-- even whether my .jpeg screenshot image here
might look different (brighter) on other peoples' monitors than my own!

Posting .png images is something I rarely do (if ever?); I should do a test and
upload a .png here, to see if the *posted* result matches its original
appearance on my system. (But more importantly, to see if its tonal range
matches the 'overall appearance' of other .png's posted on the newsgroup.)

The last POV-Ray image I made and uploaded was my 'matchmoving' experiment, as a
..jpeg-- found here...

http://news.povray.org/*/attachment/%3Cweb.52fd49177094def7c2d977c20%40news.povray.org%3E/matchmoving_still_frame.jpg

On my own system, that one looks identically the same on the newsgroup page (and
as a download) compared to my original. But does it possibly look 'washed out'
on your monitor (and/or on LCD monitors)? That's a subjective question, of
course, but it would be helpful for me to know.


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